Headings should express the original hierarchy
A good conversion preserves the relative depth of sections instead of flattening everything into plain paragraphs. When heading levels collapse, the reader loses the document map and downstream systems lose a strong signal for chunk boundaries. You want output where a section can stand on its own because the hierarchy around it still makes sense.
Lists need to remain logically grouped
Business documents often use bullets to communicate dependencies, requirements, or follow-up steps. If those bullets break into wrapped paragraphs or drift apart, meaning is lost. Clean Markdown keeps lists intact, preserves nested items where possible, and avoids introducing spacing that makes one list item look like the start of a new section.
Tables should be readable even when imperfect
Not every complex spreadsheet or slide table will translate beautifully to Markdown, but good output still communicates row and column intent. A useful conversion favors intelligibility over exact visual geometry. If the table cannot survive as a valid Markdown table, a structured textual fallback is often better than a collapsed paragraph of cell contents.
Code, quotes, and inline semantics matter
Technical and policy documents both benefit from preserving small semantic markers. Code blocks, inline code, quotations, callouts, and emphasis are not decoration when they change how text should be interpreted. Markdown is strong because these signals are lightweight but expressive, which makes preserving them worthwhile during conversion.
The output should be immediately usable
The simplest test is practical: can someone paste the output into a docs system, commit it to a repo, or feed it to an AI workflow without first spending ten minutes cleaning it? If yes, the conversion is doing real work. If not, the output may be technically correct while still failing the product goal.